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Before the Health and Human Services, Education and Related Agencies
February 26, 1997

Mr. Chairman, I am pleased to report that the NEI continues to conduct and support research leading to treatment for blinding eye diseases, including glaucoma, cataracts, and diabetic retinopathy. Furthermore, we also are pursuing exciting new avenues of research for one particular eye disease that is causing increased concern among older Americans , age related macular degeneration, or AMD.

The American eye is aging. The first group of "baby boomers" , those born between 1946 and 1964 , turned 50 last year. This group, by their sheer numbers, has changed, and continues to change, the fabric of American society. In 1995, these "baby boomers" numbered more than 79 million.

As this group of Americans marches toward their golden years, they will become more susceptible to serious eye diseases, such as AMD. AMD is a common eye disease of the macula, a tiny area in the retina that helps produce sharp, central vision required for "straight ahead" activities such as reading, sewing, and driving. A person with AMD loses this clear, central vision. AMD is the leading cause of severe visual impairment and blindness in the United States. It is estimated that AMD already causes visual impairment in approximately 1.7 million of the 34 million Americans over age 65, and its prevalence is expected to reach 6.3 million by the year 2030. Since fiscal year 1989, the NEI has devoted an increasing percentage of its annual appropriation to AMD research.

Technology has advanced greatly in recent years, and as a result, the NEI has identified several areas of research to learn what causes AMD and how it can be treated more successfully. Through NEI's Age-Related Eye Disease Study, researchers at 11 clinical centers around the country are assessing the aging process, potential risk factors, and quality of life of 4700 patients to pinpoint the earliest signs of AMD. Once such studies have helped us to determine how macular degeneration develops, we might be able to change its course; when we know for certain what risk factors contribute to development of the disease, we can caution patients to avoid them. This same study also includes clinical trials that will help determine the effects of certain vitamins and minerals in preventing or slowing the progress of AMD. In particular, researchers are examining whether vitamins C and E, beta-carotene, and zinc can provide the macula with greater protection, thereby preventing or slowing progression of the disease. If dietary supplements prove effective, it would have a huge impact on AMD treatment and reduce our nation's risk of visual impairment or blindness.

Another study begun last year is evaluating genetic and environmental factors related to AMD and examining an underlying hypothesis that genetic factors play a significant role in this complex chronic disease. Participating families in this study include those with both a single case of documented AMD and those who have at least two living siblings (or a parent) with documented AMD.

One of the risk factors that may be associated with AMD and vision loss is the presence of drusen, which are white, clumpy deposits that lodge under the retina. Early investigations suggest that these deposits might be a precursor to AMD, and this hypothesis is undergoing careful study to determine if drusen play a role in the development of macular degeneration.

Other approaches to solving the problem of AMD include laboratory, or basic, research. This research includes studies of genetic factors to gauge the role of heredity in the development of AMD. Genes involved in AMD already have been identified in three less common types of macular degeneration. In addition, genes associated with several other forms of macular degeneration have been localized to specific chromosomes. Knowing the genes will enable researchers to determine the gene product and how it brings about the degeneration.

NEI scientists also are trying to identify genes that could help regenerate damaged areas of the retina. This strategy may help to prevent much of the visual loss from later stages of AMD. Researchers are exploring the effects that gene replacement therapy may have on the treatment of macular degeneration, and scientists have already successfully placed genes into the retina of laboratory animals. Replacing diseased retinal cells with healthy ones is another promising area of research. NEI scientists are working to apply retinal cell transplants to treat retinal degeneration caused by AMD.

The NEI also sponsored a workshop that led to shared research ideas and consideration of the future direction of AMD research. This workshop, held last June, brought together academicians, clinicians, and representatives from biotechnology companies, all of whom were knowledgeable in growth factor cell biology. The discussion centered around the potential use of neurotrophins, or biological survival factors, to delay clinical indications of retinal cell degeneration in AMD and other eye diseases.

In addition to being a leading cause of blindness in the United States, AMD is also a leading cause of low vision, broadly defined as a visual impairment interfering with an individual's ability to perform activities of daily living. There are approximately three million Americans who suffer from visual conditions that are not correctable by standard glasses or contact lenses. People with low vision often cannot perform daily routine activities, such as reading the newspaper, preparing meals, or recognizing faces of friends.

As the leading source of vision research funds in the United States, the NEI is committed to furthering progress in the area of low vision research. During 1996, the NEI supported 18 extramural research projects related to low vision. In addition, the NEI, through the National Eye Health Education Program, is developing an education program aimed at addressing the needs of people with low vision. This new program will increase public awareness about the impact of low vision on daily living. Approximately 21 percent of those who have low vision and are aged 45 and older are unfamiliar with low vision clinical services. The low vision program will play a key role in informing Americans about the use of optical and adaptive low vision devices and services.

The NEI has been very active in pursuing treatments for a wide spectrum of eye diseases, including those affecting the youngest Americans. Last year we confirmed that a freezing treatment helps save the sight of premature babies with a potentially blinding condition called retinopathy of prematurity. After 5� years of follow-up, this treatment increased the possibility of saving sight in affected eyes by about 24 percent. These results present solid evidence that this freezing treatment significantly reduces the number of infants who are blinded by retinopathy of prematurity.

NEI's fight against uveitis, a severe inflammation in the eye, is continuing. Uveitis causes about 10 percent of the severe visual impairment in the United States, and affects primarily children and young adults. Treatment of uveitis has usually revolved around potent drugs that block the immune system. In a recent intramural NEI study, we found that when a purified protein is fed to patients suffering from uveitis, they were able to be weaned off the strong drugs, with no negative side effects. A larger, more focused clinical trial is underway.

The NEI is also studying the effect of apoptosis, or "cell suicide," in retinal degeneration. Apoptosis is a controlled, orderly process by which the body eliminates unwanted cells; it is a mechanism to eliminate damaged cells, without harming healthier neighbors. Apoptosis appears to play a role in several retinal degenerative diseases. By understanding the process by which this programmed cell death occurs, scientists may be able to develop a method to inhibit the process and thus treat these diseases.

The NEI also is active in the area of cell rescue and regeneration. Severed nerve cells in the peripheral nervous system can survive and regenerate to some extent, but most central nervous system nerve cells do not. For years researchers have been trying to determine the basis for this difference, so that damage to either system could be repaired. Recent research on the development of the visual system indicates that the signals that promote the survival and growth of neurons in the central nervous system and peripheral nervous system may differ significantly. Studies have demonstrated that specialized nerve cells in the retina that are similar to brain cells, including those cells in the spinal cord, do not survive in a serum-free culture medium. However, these cells do survive in culture when the medium contains the required combination of growth factors and other constituents. Related experiments in animals show that the survival of these specialized retinal cells after damage is significantly increased by injection of these factors into the eye. These findings demonstrate that the retinal nerve cells have similar survival requirements in the living organism and in the test tube, suggesting central nervous system neurons can be rescued by activating the appropriate signaling pathways.

As the NEI continues its research, it is becoming apparent that many eye diseases and disorders share common denominators. For example, new blood vessel growth in the retina is associated with both diabetic retinopathy and age-related macular degeneration. The NEI is looking at the way these pathologic processes cut across many diseases and can be controlled by blocking new blood vessel growth.

Our investment in high quality clinical research has little real benefit unless the results and recommendations from such studies are widely and suitably incorporated into patient care. Results of research must be disseminated to the public so people can take more proactive approaches to ensure their own health. One way this happens is through the National Eye Health Education Program (NEHEP), which is playing a role in educating Americans on the early detection and treatment of eye disease. For the past three years the National Eye Institute, through the NEHEP, has joined forces with the American Diabetes Association to make diabetic eye disease the major focus of National Diabetes Month activities, held in November. Through this successful public-private partnership, 11 organizations have disseminated important information to the 16 million Americans with diabetes and conducted community activities nationwide that emphasized the importance of an annual dilated eye examination. A related media campaign focusing on the connection between diabetes and eye care reached over 80 million people.

NEI's research program does more than fight eye disease , it also helps inventors with ideas on low vision aids develop those ideas for the marketplace. Inventors have few resources available allowing them to develop products that help people suffering from low vision. NEI's Small Business Innovation Research Grants Program gives inventors the opportunity to see their ideas turned into reality. For example, through this program, telescopic systems were developed that help those with low vision perform common tasks, such as walking down the street or reading signs. Another idea, a system called "Outspoken," magnifies text on a computer screen, making it easier for people with low vision to read. This product was recognized by the Smithsonian Institution for its unique way of using technology for the common good. A sister program, called the Small Business Technology Transfer Grant, encourages inventors in universities or research centers to form partnerships with small businesses. Between both programs, NEI expects to fund approximately 50 projects this fiscal year.